It's a slightly formal and old-fashioned word, often used in the phrase "it behooves someone to do something".
Here are some examples:
* It behooves us to be respectful of other cultures. (It is necessary or appropriate for us to be respectful.)
* It behooves a good leader to listen to their team. (It is incumbent upon a good leader to listen.)
Essentially, when something behooves you, it means it is your duty or responsibility to do it.